This invention generally relates to the art of electrical connectors and, particularly, to a filter connector which mounts a plurality of electronic components, such as capacitors or the like. The invention also relates to a method of fabricating the filter connector. The filter connector can have modular characteristics.
There are a variety of electrical connectors which are termed “filter” connectors, in that an electronic component, such as a capacitor, is coupled between the terminals of the connector and a ground plate or shorting bar normally mounted to a face of a dielectric housing of the connector. The filters are used to suppress electromagnetic interference and radio frequency interference entering the connector system.
One of the problems with such filter connectors simply is their cost. Normally, a ground plate is fabricated of stamped and formed conductive metal material and must be mounted separately to the dielectric housing of the connector. Terminals then are mounted in the connector housing. The filter capacitors then must be coupled between the terminals and the ground plate or shorting bar. These steps are time consuming and require assembly tooling, all of which adds considerably to the cost of the connectors. In a mass production environment, reliability and performance are desired. Typically, the terminals are mounted or inserted into a connector housing in one direction, the capacitors are mounted or inserted into the housing in a different direction, and the ground plate or shorting bar is mounted or assembled in the same or different direction. All of these assembly operations require relatively expensive assembly tooling.
Some prior approaches use capacitor arrays, sometimes referred to as monolithic capacitors, in providing filtering functions within connectors. Examples of approaches in this regard include Brancaleone U.S. Pat. No. 4,371,226 and Reider et al. U.S. Pat. No. 5,509,825. While recognized by Brancaleone as a deficiency, the capacitor array approach is compounded by a shield design having large openings that allow EMI/RFI to pass through the assembly. Also, compared with the relatively few components according to the present invention, Brancaleone has additional parts, leading to increased assembly time and cost. In addition to the teaching to use capacitor arrays, Reider requires a “zebra strip” to provide compliance between the capacitor and the pins to compensate for the capacitor array being planar while the pins are not always in the same exact plane. The zebra strip of Reider has the negative of adding inductance and resistance to the filter circuit and additional cost.
Ward U.S. Pat. No. 5,624,277 shows a stamped and formed cantilever spring having spring fingers. The cantilever spring establishes a connection between the capacitors and the contact terminals. This arrangement shows open ends that do not provide adequate EMI/RFI transmission. Farrar et al. U.S. Pat. No. 4,820,174 shows a ground plate that includes a plurality of spring finger openings for receiving a tubular filtered contact assembly. Mounting of this ground plate is facilitated by integral spring fingers that engage the conductive shell of this connector assembly with filtered inserts. This approach requires a relatively complex filter contact assembly.
Through the inventive efforts of the present disclosure there is a reduction in the number of components, and these reduced number of components achieve grounding and shielding while providing secure electrical contact between the input and output side of the connector and the shielding components positioned there along. This inventive approach reduces cost and complexity and reduces EMI/RFI emissions through the header of the filter connector.
In some circumstances it can be desirable to provide a filter connector in which the terminals and filters/capacitors are mounted in modules and assembled in a larger outer connector housing. By such a modular approach the outer housing of the filter connector can be molded in different sizes to customize the connector to meet a need for a specific size and/or shape. These different numbers of modules are oriented to comply with the customized design. This is considerably less complicated and less expensive than customizing an entire connector for different numbers of terminals and filters.